A control system may include a combination of components (electrical, mechanical, thermal, hydraulic, etc.) that act together to maintain system performance close to a desired set of performance specifications. Common types of control systems may include open-loop control systems and closed-loop control systems. Open-loop control systems are those in which the output does not affect the input. Examples of open-loop control systems may include control systems for an automatic toaster or an alarm clock. Closed-loop control systems are those in which the output has effects on the input in such a way as to maintain a desired output value. Examples of closed-loop control systems may include thermostats, engine governors and automotive cruise-control systems.
Components in a control system may be changed to modify operation of the control system. The process of changing the parameters of the components of a control system is referred to as “tuning” the control system. A conventional approach for tuning control systems is to treat a compensator as a single element. A “compensator,” as used herein, refers to a gain or dynamic system whose parameters are manipulated to modify the performance of a control system. Tuning control systems may be necessary for many reasons, such as to include traditional software architecture organization, to address the need for controller mode shifting or to model initialization considerations.
Compensators may be formed of multiple components. If the compensator can be represented as a single element, the user may tune the parameters of one element as opposed to parameters of the multiple components forming the compensator. However, it is often problematic to represent a compensator as a single element in a free form modeling environment, where a given compensator can spread across multiple components. In a free form modeling environment, the users may create designs as if using a whiteboard. The user may create objects and relationships without concern about incomplete specifications, consistent typology, or formal correctness. As such, it may be very difficult for a user to define boundaries of a compensator in a free form modeling environment.